Insulating jacket for fluid lines and the like



OGL 23, 1962 v F. E. slNDRs 3,060,069

INSULATING JACKET FOR FLUID LINES AND THE LIKE Filed Oct. 23. 1959 IIIIA ZM/Evra@ y. 6Fl/QED E. 5mm/:1195,

United States PatentOi 3,060,069 INSULATING JACKET FOR FLUID LINES AND THE LIKE Fred E. Sind'ars, 367 Alondra St., Gardena, Calif. Filed Oct. 23, 1959, Ser. No. 848,442 11 Claims. (Cl. 154-45) The present invention relates in general to insulating jackets forapplication to members to be insulated and, more particularly, to insulating jackets for minimizing heat transfer to or from ythe insulated member-s, a primary object of the invention being to provide a sheet-like insulating jacket which is adapted to enclose the member to be insulated and which includes means engageable with the insulated member for spacing portions of the jacket outwardly from the insulated member to provide substantially dead air spaces around the member.

The invention is particularly applicable to a tubular insulating jacket for heat insulating such elongated members as fluid conductors, electrical conductors, and the like. For convenience in disclosing the invention, it will be considered herein as embodied in a tubular insulating jacket for application to relatively small uid lines, such as fuel lines, hydraulic lines, and the like, which are to be insulated against heat transfer thereinto. However, it will be under-stood that the invention is susceptible of vother applications.

An important object of the invention is to provide a tubular insulating jacket for a member such as a fluid line which jacket is formed with spaced indentations providing spaced internal ribs engageable with the member, the insulating jacket being spaced outwardly from the member between the internal ribs to provide substantially dead air spaces therebetween.

More particularly, an important object is to provide a tubular insulating jacket having longitudinally spaced,

Acircumferential indentations which provide the tube with longitudinally spaced, circumferential internal ribs engageable with the member and providing dead air spaces therearound. In some embodiments of the invention, the longitudinally spaced indentations and internal ribs are -annular while, in others, they are helical.

Another object is to provide tubular insulating jackets wherein the circumferential indentations are closely spaced where flexibility is required to accommodate bends in the member to be insulated, and to provide tubular insulating jackets wherein the circumferential indentations are spaced relatively far apart longitudinally of the jacket where such flexibility is not required.

Another object is to provide a tubular insulating jacket having one or more portions provided with closely spaced indentations to render such portions flexible to accommodate tubing bends, and the like, and having one or more portions wherein the circumferential indentations are spaced relatively far apart to accommodate straight tubing sections. A related object is to provide such a tubular insulating jacket wherein the portions mentioned are either integral, or are separate tubes having overlapping ends.

- circumferentially continuous.

An important object of the invention, however, is to ice provide a tubular insulating jacket which is longitudinally split so that it may be slipped onto a previously installed member laterally by separating the jacket' at the longitudinal split therein, the jacket being sufficiently resilient to close around the member after it is slipped laterally there/onto. Another object in this connection is to provide a longitudinally-split tubular insulating jacket which has overlapping longitudinal edges to insure circumferential continuity of the insulating effect of the jacket upon installation.

Another object is tomake the tubular insulating jacket of the invention in the form ,of a plastic sheet, and particularly a reinforced plastic sheet. Preferably, the jacket is formed of an elastomeric material having a brous reinforcing material, such as glass, cloth, asbestos, or the like, embedded therein. In some instances, however, the jacket may include a metallic reinforcing material.

Another object of lthe invention is to provide the insulating jacket with a radiant heat reflecting surface to assist in minimizing heat transfer, the reflecting surface being either the inner or the outer surface of the jacket, depending on whether outward or inward heat transfer is to be minimized.

The lforegoing objects, advantages, features and results of the present invention, together with various other objects, advantages, features and results thereof which will vbe evident to those skilled in the art in lthe light of this disclosure, may be achieved with the exemplary embodiments of the invention described in detail hereinafter and illustrated in the accompanying drawing, wherein:

FIG. l is a semidiagrammatic view, partially in section 4and partially in elevation, illustrating one embodiment of the invention as installed on a iluid line;

FIG. 2 is an enlarged view, partially in longitudinal section and partially in elevation, illustrating in more detail the embodiment of the invention which is shown inv FIG. 1;

FIG. 3 is an exploded view showing components of the embodiment of FIG. 2 prior to assembly;

FIG. 4 is a View similar to FIG. 3, but showing the components illustrated therein in assembled condition;

=FIG. 5 is a transverse sectional view of the embodiment i of FIG. 2;

bodiment of FIG. 2 in place on a fluid line;

FIG. 8 is a perspective View of another embodiment of the invention;

FIGS. 9 and l() are elevational views respectively showing still other embodiments of the invention; and

FIGS. ll and l2 are fragmentary longitudinal sectional views respectively showing still other embodiments of the invention.

Referring iirst to FIG. l of the drawings, illustrated 'therein is a tubular insulating jacket 20 of the invention in place on a fluid line 22. The latter may be a fuel line, hydraulic line, or the like, and is shown as connected at its ends to fittings 24 in a conventional manner. The fluid line 22 is shown as provided intermediate its ends with bends 26 and straight, or substantially straight, sections 2S.

The jacket 20, which will be described in morerdetail hereinafter, comprises a relatively flexible sheet formed into a tube of a size to receive the lluid line 22. The jacket is provided with a plurality of annular indentations or corrugations which form internal annular ribs 32 engageable with the fluid line 22. The internal ribs 32 space the jacket outwardly from the fluid line 22 to provide between the ribs dead air spaces 34 which act to minimize heat ilow to or from the lluid line, depending upon the direction of any temperature differential between the fluid line and the surrounding atmosphere. As will be discussed hereinafter, the material of the jacket 20 itself has heat insulating qualities which further minimize heat transfer. Also, the jacket 2t) may be provided with a radiant heat reflecting coating 36, FIGS. 3 and 4, such coating being either on the inner surface or the outer surface of the jacket depending upon whether outward or inward heat flow is to be minimized.

The jacket 20 is provided with portions 38 at the bends 26 wherein the indentations 30 and ribs 32 are quite closely spaced to render the jacket 2t) sulciently flexible in the vicinities of the bends to accommodate them readily. Preferably, the ribs 32 are longitudinally spaced apart throughout the flexible portions 38 distances of the order of the longitudinal dimensions of the ribs to achieve the desired flexibility.

However, the ribs 32 are spaced apart considerably farther throughout pontions 4Q of the jacket 20 which are designed to fit the straight sections 28 of the fluid line 22.` Preferably, the longitudinal spacing of the ribs 32 throughout the portions 40 of the jacket 2li is several times the longitudinal dimensions of the ribs. Such increased spacing of the ribs 32 throughout the portions 40 of the jacket 2l) reduces the heat llow through such portions, as compared to the heat llow through the flexible portions 38, for several reasons. First, the area of contact between the jacket 2t) and the lluid line 22 is reduced by increasing the spacing of the ribs 32 in the portions 4tl. Secondly, the volume of the dead air spaces 34 in the portions 4t) is increased. Third, more radiant heat is reflected away by the use of relatively long unindented or uncorrugated sections throughout the portions 40, it being apparent that, Y

in the ilexible portions 38, some of the reflected radiant heat is reflected against the surfaces of the indentations 30 so that more of it is transmitted through the j-acket. Thus, by using closely spaced indentations 30 and ribs 32 only where necessary for flexibility, the over-all heat flow through the jacket 20 is minimized, which is an important feature.

Considering the physical characteristics of the jacket 2t, it comprises, in effect, -a plastic sheet formed into a tube. More particularly, the wall of the jacket Ztl preferably comprises a reinforced plastic material, the reinforcement preferably being fibrous in nature, although other reinforcing materials may be used, and the plastic material being elastomeric, although nonelastomeric materials may be utilized in some instances, such as, for example, where the jacket is to be used only on straight members and is adapted to be slipped over the ends `of such members.

FIG. 3 shows a cross section of a fragment of the wall of the jacket 20 prior to assembly, the jacket wall being shown as including a reinforcing layer 42 which is preferably glass cloth, but which may be asbestos mat, asbestos cloth, or cloth of a material such as nylon, rayon, or the like. In some instances, the layer 42 may even be metallic cloth for greater strength, electrical continuity, or the like. The layer 42 is provided on one side with the radiant heat rellecting coating 36, which may be an aluminum coating applied by vapor deposition. However, other reflective materials may be used. If the coating 42 is uniformly applied throughout the entire length of the jacket 20, it is made thin enough to provide the required ilexibility throughout the flexible portions 38 of the jacket. However, the rellective coating may be applied non-uniformly with sufficient thickness to rigidify at least to some extent portions which are not required to flex.

The reinforcing layer 42 is impregnated with a plastic l material, preferably an yelastomeric material such as rubber, and, in the construction shown, is provided with a coating 44 of the same or a similar material. The purpose of the coating 44 is to permit bonding to the reinforcing layer 42 a second reinforcing layer Yor ply 46, which is also impregnated with a material the same as or similar to that of the reinforcing layer 42 and the coating 44. FIG. 4 of the drawing shows the two reinforcing layers or plies 42 and 46 bonded together, as by Vulcanizing, or otherwise curing, the plastic material employed.

As will be apparent, the'tubular jacket 2t) may be slipped over an end of a fluid line prior to connecting such end of the fluid line to a iitting, or the like. However, an important feature of the invention is that the jacket 20 may be installed on a fluid line, such as the fluid line 22, with the line in place and connected at its ends to the fittings 24, for example. To achieve this, the jacket 20 is longitudinally split and is suillciently llexible that it may be slipped -onto the fluid line 22 laterally, as shown in FIG. 6, by separating the longitudinal edges of the jacket `sufficiently to receive the fluid line therebetween. Thus, the jacket 20 may be applied readily to existing fluid lines.

In order to provide an insulating elfect which is circumferentially continuous, the longitudinal edges of the jacket Ztl overlap sufficiently, as shown in FIG. 7, upon installation on the fluid line to render the insulating qualities of the jacket in the vicinity of the joint between the longitudinal edges thereof substantially equal to the insulating qualities thereof intermediate the longitudinal edges. As shown in FIG. 5, the jacket 2t) is formed initially with a somewhat greater overlap between the longitudinal edges thereof than exists in the iinal installation, shown in FlG. 7. The reason for this is to have the jacket 20, when installed on the fluid line 22, in a somewhat stressed condition so that it will tend to close around the fluid line and thus cling thereto in a positive manner. In other words, the jacket 2o tends to resume the original configuration shown in FIG. 5, and thus irmly grips the fluid line 22 when installed thereon as shown in FIG. 7. It will be understood that the jacket 20 is cured initially while in the original configuration of FIG. 5 so that it always tends to resume this configuration.

Referring now to FIG. 8 of the drawing, illustrated therein is a tubular insulating jacket 50 of the invention which is similar to the portions 40 of the jacket 20, except that it is not longitudinally split. The jacket 50 is designed to be utilized `on a straight -iluid line, electrical conductor, or the like, and to be slipped over one end thereof. However, the jacket Stb mayV also be provided with flexible portions, not shown, similar to the llexible portions 38 of the jacket 20, to accommodate bends.

FIGS. 9 and l() of the drawing respectively show tubular insulating jackets 60 and 70 which are similar to the jacket Ztl, or the jacket 50, except that they are provided with circumferential indentations 62 and 72, respectively, which are -closely spaced throughout the entire lengths of these jackets. Thus, the jackets 6i) and 70 are similar to the llexible portions 38 of the jacket 20` throughout their entire lengths and are llexible throughout their entire lengths. The jackets `60 and 70 differ in that the indentations 62 of the jacket `6G are helical, while the indentations 72 of the jacket 70 are annular. As will be apparent, the jacket 6o provides a single, helical air space when installed on a member `to be insulated, whereas the jacket 70 provides a plurality of separate, longitudinally spaced air spaces. Thus, the jacket 70 is more effective from the standpoint of minimizing heat ilow since the air spaces provided thereby are actually dead air spaces, whereas there can be some air flow from'one end of-the air space lof the jacket 60 to the other unless the ends of such air space are completely closed upon installation of the jacket 60.

Referring to FIG. ll of the drawing, illustrated therein is a tubular insulating jacket `.",ll which is similar to the jacket 20 in that it includes a flexible portion :82 having closely spaced indentations and internal ribs 84 and S6 and includes less flexible portions 88 having more widely spaced indentations and internal ribs 90 and 92. The jacket'80 diiers from the jacket 20 in that the flexible portion 82 and the more rigid portions 88 are separate tubes overlapped at their adjacent ends. As shown, the internal rib 86 at one end of the portion '8,2 is disposed in the indentation 90 at the adjacent end of one of the portions `88. At the other end of the portion 82, one of the ribs 92 of the other portion 88 is disposed in the endmost indentation `84, of the portion 82. However, this specific overlapping relation between the portions 82. and 88 may be varied as -dictated by the conditions under which they are to be used. The portions 82 and 88 of the jacket 80 may either be circumferentially continuous, or they may be longitudinally split.

FIG. 12 of the drawing shows a tubular insulating jacket 100 which is similar to one of the portions 40 and 88 of the jackets 20 and 80 in that it includes relatively widely spaced indentations 102 forming internal ribs 104. The jacket -100 diers in that it is provided with additional reinforcing elements 106 embedded, as by molding, in the wall of the jacket 100. These reinforcing elements may be made of any suitable material, such as a plastic material, or a metallic material. The jacket 100 may be circumferentially continuous, or it may be longitudinally split in the same manner as the jacket 20. In the latter event, the reinforcing elements 106 are suiciently flexible to permit slipping the jacket 100 laterally onto a member to be insulated. In this instance, the reinforcing elements 106 assist in gripping the insulating member.

Although several exemplary embodiments of the invention have been disclosed herein for purposes of illustration, it will be understood that other embodiments oi the invention are possible and that various changes, modifications and substitutions may be incorporated in the embodiments disclosed, all without departing from the spirit of the invention as dened by the claims which follow.

I claim:

1. A heat insulating jacket for such members as lluid lines, electrical conductors, and the like, comprising a heat insulating tube adapted to receive therein a member to be insulated, said tube having longitudinally spaced indentations therein which provide said tube with longitudinally spaced internal ribs engageable with the member, said tube being spaced outwardly from the member between said internal ribs to provide substantially dead air spaces therebetween, and said tube having a radiant heat reiiecting coating.

2. A tubular jacket of ilexible heat insulating material having longitudinally spaced indentations therein which provide said jacket with longitudinally spaced internal ribs, said jacket having a portion in which said internal ribs are longitudinally spaced lapart ldistances of the order of the longitudinal dimensions of said internal ribs, and said jacket having another portion in which said internal -ribs are longitudinally spaced apart distances several times the longitudinal dimensions of said internal ribs, the outside di-ameters of said portions of said jacket being substantially equal.

3. A tubular jacket of exible heat insulating material having longitudinally spaced indentations therein which provide said jacket with longitudinally spaced intern-al ribs, said jacket having a portion in which said internal ribs are longitudinally spaced apart distances of the order of the longitudinal dimensions of said internal ribs, and said jacket having another portion in which said internal ribs are longitudinally spaced apart distances several times the longitudinal dimensions rof said internal ribs, the outside diameters of said portions of said jacket being substantially equal, said portions of said jacket being integral.

4. A tubular jacket of exible heat insulating material having longitudinally spaced indentations therein jwhich provide said jacket with longitudinally spaced internal r-ibs, said jacket having a portion in which said internal ribs are longitudinally spaced apart distances of the order of the longitudinal dimensions of said internal ribs, and said jacket having another portion in which said internal ribs are longitudinally spaced apart distances several times the longitudinal dimensions of said internal ribs, the outside diameters of said portions of said jacket being substantially equal, said por-tions of said jacket being separate tubes having overlapping ends.

5. A tubular heat insulating jacket of ilexible material having longitudinally spaced indentations therein which provide said jacket with longitudinally spaced internal ribs, said jacket 'having -a portion in which said internal ribs are longitudinally spaced apart distances of the Order of the longitudinal dimensions of said internal ribs, said jacket having lanother portion in which said internal ribs `are longitudinally spaced apart distances several times the longitudinal dimensions of sa-id internal ribs, the outside `diameters of said portions of said jacket being substantially equal, said jacket being longitudinally split and having overlapping longitudinal edges, and said jacket being resilient so that i-t is inherently biased toward a cross sectional coniiguration wherein said longitudinal edges overlap.

6. A tubular jacket of flexible heat insulating material having longitudinally spaced indentations therein which provide said jacket with longitudinally spaced internal ribs, said jacket being longitudinally split fand having overlapping llongitudinal edges, and said jacket being resilient so that it is inherently biased toward a cross sectional conguration wherein said longitudinal edges overlap.

7. A tubular heat insulating jacket having indentations therein which provide said jacket with internal ribs, said jacket being longitudinally split and having overlapping longitudinal edges, and said jacket being resilient so that it is inherently biased toward a cross sectional cong'uration wherein said longitudinal edges overlap.

8. A tubular jacket of llexible heat insulating material having longitudinally spaced indentations therein which provide said jacke-t with longitudinally spaced internal ribs, said jacket having a por-tion in which said internal ribs are longitudinally spaced apart distances of the order of the longitudinal dimensions of said internal ribs, and said jacket having another portion in which said intern-a1 ribs are longitudinally spaced apart distances several times the longitudinal dimensions of said internal ribs, the outside diameters lof said portions of said jacket being substantially equal, said other portion of said jacket having reinforcing elements embedded therein intermediate said internal ribs thereof.

9. A tubular heat insulating jacket `formed of a br-ous material impregnated with Ian elastomeric material and having longitudinally spaced indentations therein which provide said jacket with longitudinally spaced internal ribs, said jacket being longitudinally split Iand having overlapping longitudinal edges, and said jacket being resilient so that it is inherently biased toward a cross sectional configuration wherein said longitudinal edges overl-ap.

l0. A two-piece tubular jacket 4of eXible heat insulating material having pieces telescoped together in end-toend relation, one of the pieces of said jacket having internally thereof means for spacing it lradially outwardly from a member therein which is to be insulated, the other piece of said jacket having longitudinally spaced internal ribs spaced apart distances of the order of their longitudinal dimensions.

1l. A tubular jacket of flexible heat insulating material having means internally thereof for spacing it radially outwardly from a member therein to be insulated, said jacket being longitudinally split and having overlapping longitudinal edges, and said jacket being resilient s0 that it is inherently biased toward a cross sectional coniiguration wherein said longitudinal edges overlap, where- 7 by said jacket may lne slipped laterally onto la member to be insulated by spreading said longitudinal edges apart suciently to receive the member therebetween, the resilience of said jacket subsequently causing said longitudinal edges to resume an Overlapping relation with said jacket spaced radially outwardly from the member to be insulated.

References Cited in the le of this patent UNITED STATES PATENTS 1,838,242 Wilson Dec. 29, 1931 8 Schmidt Sept. 27, 1949 Cross et al. Sept. 10, 1957 Waite et al Sept. 24, 1957 `Frink Dec. 16, 1958 Roberts June 23, 1959 Kilcup Aug. l1, 1959 'Childers May 10, 1960 Tillotson Aug. 29, 1961 Newsome et al. Dec. 12, 1961 

7. A TUBULAR HEAT INSULATING JACKET HAVING INDENTATIONS THEREIN WHICH PROVIDE SAID JACKET WITH INTERNAL RIBS, SAID JACKET BEING LONGITUDINALLY SPLIT AND HAVING OVERLAPPINGG LONGITUDINAL EDGES, AND SAID JACKET BEING RESILIENT SO THAT IT IS INHERENTLY BIASED TOWARD A CROSS SECTIONAL CONFIGURATION WHEREIN SAID LONGITUDINAL EDGES OVERLAP. 